1. Field of the Invention
The purpose of this invention is to permit determinations regarding blood.
2. Description of the Art Practices
The reader is referred to the following articles and publications:    1. C. E. Riva, B. Ross, and G. B. Benedek, “Laser Doppler measurements of blood flow in capillary tubes and retinal arteries,” Invest. Opthalmol. 11, 936-944 (1972).    2. G. T. Feke and C. E. Riva, “Laser Doppler measurements of blood velocity in human retinal vessels,” J. Opt. Soc. Am. 68 (4), 526-531 (1978).    3. C. E. Riva, G. T. Feke, B. Eberli, and V. Benary, “Bidirectional LDV system for absolute measurement of blood speed in retinal vessels,” Appl. Opt. 18, 2301-2306 (1979).    4. C. E. Riva, J. E. Grunwald, S. H. Sinclair, and B. L. Petrig, “Blood velocity and volumetric flow rate in human retinal vessels,” Invest. Opthalmol. Vis. Sci. 26, 1124-1132 (1985).    5. B. L. Petrig and C. E. Riva, “Retinal laser Doppler velocimetry: towards its computer-assisted clinical use,” Appl. Opt. 27, 1126-1134 (1988).    6. E. Logean, L. F. Schmefterer, and C. E. Riva, “Velocity profile of red blood cells in human retinal vessels using confocal scanning laser Doppler velocimetry,” Laser Phys. 13, 45-51 (2003).    7. B. L. Petrig and L. Follonier, “New ray tracing model for the estimation of power spectral properties in laser Doppler velocimetry of retinal vessels,” ARVO Abstract (2005).    8. S. Wolfram, Mathematica Book, 5th ed. (Wolfram Media, Inc., 2003).    9. D. U. Fluckiger, R. J. Keyes, and J. H. Shapiro, “Optical autodyne detection: theory and experiment,” Appl. Opt. 26, 318-325 (1987).    10. C. E. Riva, B. L. Petrig, and J. E. Grunwald, “Retinal blood flow,” in Laser-Doppler blood flowmetry, A. P. Shepherd and P. A. Oberg, eds., pp. 349-383 (Kluwer Academic Publishers, 1989).    11. J. B. Lastovka, “Light mixing spectroscopy and the spectrum of light scattered by thermal fluctuations in liquids,” Ph.D. thesis, Massachusetts Institute of Technology (1967).    12. C. E. Riva and G. T. Feke, “Laser Doppler velocimetry in the measurement of retinal blood flow,” in The Biomedical Laser: Technology and Clinical Applications, L. Goldman, ed., pp. 135-161 (Springer, N.Y., New York, N.Y., USA, 1981).    13. O. W. van Assendelft, Spectrophotometry of hemoglobin derivatives (C. C. Thomas, Springfield, Ill., USA, 1990).    14. D. Schweitzer, M. Hammer, J. Kraft, E. Thamm, E. K“onigsd”orffer, and J. Strobel, “In vivo measurement of the oxygen saturation of retinal vessels in healthy volonteers,” IEEE Trans. Biomed. Eng. 46, 1451-1465 (1999).    15. A. Ishimaru, Wave Propagation and Scattering in Random Media, vol. II (Academic Press, New York, 1978).    16. C. E. Riva, J. E. Grunwald, and B. L. Petrig, “Laser Doppler measurement of retinal blood velocity: validity of the single scattering model,” Appl. Opt. 24, 605-607 (1985).    17. A. Harris, R. B. Dinn, L. Kagemann, and E. Rechtman, “A review of methods for human retinal oximetry,” Ophthal. Surg. Las. Im. 34, 152-164 (2003).    18. F. C. Delori, “Noninvasive technique for oximetry of blood in retinal vessels,” Appl. Opt. 27, 1113-1125 (1988).    19. B. Khoobehi, J. M. Beach, and H. Kawano, “Hyperspectral imaging for measurement of oxygen saturation in the optic nerve head,” Invest. Opthalmol. Vis. Sci. 45, 1464-1472 (2004).    20. Optical Absorption of Hemoglobin by Scott Prahl, Oregon Medical Laser Center http://omlc.ogi.edu/spectra/hemoglobin/index.html.    21. Tabulated Molar Extinction Coefficient for Hemoglobin in Water 7 Pages http://omlc.ogi.edu/spectra/hemoglobin/summary.html.
Oxygen supply to the retina from the retinal and choroidal circulations at normal and increased arterial oxygen tensions, C. T. Dollery, C. J. Bulpitt, and Eva M. Kohner Volume 8 Number 8 pages 588-594 (1969).
The reader is further referred to U.S. Pat. No. 4,425,924 issued to Riva, et al. on Jan. 17, 1984 describing a method for determining the speed of leukocytes in retinal capillaries comprises the steps of simulating, by means of a minicomputer system which includes a visual display, the motion of entoptically seen leukocytes in retinal capillaries; observing entoptically the motion of actual leukocytes in the retinal capillaries of the subject's own eye; and comparing the appearances and motions of the visual display and the actual leukocytes. Apparatus for performing such a method comprises a minicomputer, a graphic display, and a display—processor interface. The reader is further referred to U.S. Pat. No. 4,476,878 issued to Riva, et al. on Oct. 16, 1984 that is a division application of U.S. Pat. No. 4,425,924.
The reader is further referred to U.S. Pat. No. 5,900,928 issued to Riva, et al. on May 4, 1999 describing an apparatus is provided for the measurement of the velocity of blood flowing within a blood vessel of an eye wherein the apparatus includes a light source for producing a source beam of light and an optical element for applying the source beam of light to the blood vessel to permit the blood flowing within the blood vessel to scatter a portion of the source beam of light and produce bidirectional scattered beams. A detector system for detecting the bidirectional scattered beams provides signals representative of the scattered beams. The light source and the detector system are disposed in a confocal relationship. An output representative of the velocity of the blood flow velocity is produced in accordance with the signals. The light source and the detector system include respective pinholes wherein the respective pinholes are disposed in the confocal relationship. The blood vessel is conjugate with the respective pinholes of the light source and the detector system. The angle between the bidirectional scattered beams is determined and a measurement of blood flow velocity is determined according to the angle.
To the extent that the foregoing references are relevant to the present invention, they are herein specifically incorporated by reference. Certain portions of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
The article Doppler velocimetry of retinal vessels and application to retinal vessel oximetry by Benno L. Petrig and Lysianne Follonier 2005 OSA 26 Dec. 2005/Vol. 13, No. 26/OPTICS EXPRESS 10642 is specifically incorporated herein by reference.